Pipe joint seal

ABSTRACT

A pipe joint seal for pipes in the form of a tubular member having beveled ends is provided. The tubular member is adapted for disposition in recesses of aligned flanged pipes connected together under stressed conditions, such as bolts, studs or clamps. Outer annular marginal grooves near the ends of the tubular members are provided to form nose sections which concentrate distortion under stressed conditions of said tubular members at the ends thereof. The annular surface of the recesses in said pipes generally conform to the exterior shape of said tubular member in the area between said marginal grooves but slope away from the exterior of said tubular member in the region between said grooves and the ends of said tubular members, thereby forming an annular shoulder in alignment with said grooves. In a stressed condition the nose sections of said tubular member are constrained to conform to the shape of the recesses above and below said shoulders. The shoulders in conjunction with the conforming shape of the tubular members retard any axial movement of the respective pipes from the expansion of said bolts or any other means due to very high temperatures. The ends of the recesses may be blunt; or, alternatively, may be beveled to conform to the shape of the beveled ends of said tubular members.

Uted States Patent 1 Tillman, III

[111 3,749,426 July 31, 1973 PIPE JOINT SEAL [76] inventor: CassiusTillman, Ill, PO. Box 343,

Peters Rd., Harvey, La.

22 Filed: July 31,1972

211 Appl. No.: 276,533

Emmerson 277/235 Primary Examiner-Thomas Callaghan Attorney-Herbert M.Birch, Anthony L. Birch et a1.

[57] ABSTRACT A pipe joint seal for pipes in the form of a tubularmember having beveled ends is provided. The tubular member is adaptedfor disposition in recesses of aligned flanged pipes connected togetherunder stressed conditions, such as bolts, studs or clamps. Outer annularmarginal grooves near the ends of the tubular members are provided toform nose sections which concentrate distortion under stressedconditions of said tubular members at the ends thereof. The annularsurface of the recesses in said pipes generally conform to the exteriorshape of said tubular member in the area between said marginal groovesbut slope away from the exterior of said tubular member in the regionbetween said grooves and the ends of said tubular members, therebyforming an annular shoulder in alignment with said grooves. in astressed condition the nose sections of said tubular member areconstrained to conform to the shape of the recesses above and below saidshoulders. The shoulders in conjunction with the conforming shape of thetubular members retard any axial movement of the respective pipes fromthe expansion of said bolts or any other means due to very hightemperatures. The ends of the recesses may be blunt; or, alternatively,may be beveled to conform to the shape of the beveled ends of saidtubular members.

9 Claims, 4 Drawing Figures PIPE JOINT SEAL This invention relates to apipe joint sealing means for pipes which is an improvement over the pipejoint sealing means described in my prior U.S. Pat. No. Re 27,389 issuedJune l3, I972. It is intended to incorporate by reference the subjectmatter of that patent herein.

The pipe joint sealing means of my foregoing mentioned patent suffersfrom the disadvantage that at extremely high temperatures the bolts orstuds which hold the respective pipe flanges together tend to expandaxially thus allowing the pipe flanges to part and weakening the seal atthe pipe joint.

Accordingly, it is an object of the present invention to provide a pipejoint sealing means which will retard axial completion of the pipesections due to axial expansion of the surrounding parts or other axialforces.

It is a further object of the present invention to provide a pipe jointseal which confines distortion under stressed conditions of the sealingmeans to end portions spaced from the location of the interface betweenthe pipe sections.

A further object of the invention is the provision of such an improvedseal which retains all advantages of the seal of my foregoing mentionedpatent including reduced turbulence of fluid passing through the joint,antiventuri action, tight fitting, reduction of hazards of handlingdangerous fluids, and the capability of installation without the use sspecial tools or equipment.

Still further objects,.advantages and features of the invention will beapparent from the following description considered together with theaccompanying draw- The present invention is intended for use with pipeshaving diameters in the range of from inch to 6 inches. However, it maybe used with pipes of larger diameters, if desired, without departingfrom the spirit and scope of this invention. The seal of the presentinvention has been tested to withstand pressures in the range of 6,000pounds at 1,400 F. This provides a considerable advance over. sealsknown in the prior art.

FIG. 1 is a cross-sectional view of the tubular sealing member of thepresent invention in an unstressed state.

FIG. 2 is a cross-sectional view of thetubular sealing member of thepresent invention in a stressed state.

FIG. 3 is a second embodiment of the invention showing a collar formedwith the tubular member adapted to beclamped between the flanges of thepipe seal; and

FIG. 4 is a third embodiment of the invention showing shims or washersbetween the flanges of the pipe seal disposed about the stud means toprevent distortion of the flanges against the collar shown between theflanges.

Referring with more particularity to FIGS. 1 and 2 of the drawing, theembodiment illustrated comprises a tubular member 11 adapted to bedisposed at either end in recesses 12 and 13 of aligned abutting pipes14 and 15. The inner ends 16 and 17 of the recesses are either blunt orbeveled at a suitable angle. The pipes typically contain flanges l8 and19 by means of which the joint is tightened with conventional flangestuds 20 and nuts 21. Other joint means may be used such as conventionalunions or clamps not shown.

The tubular member 11 has the same internal diameter as that of thepipes 14 and 15 and is provided with beveled ends 22 and 23. Member 11provides a flush surface at the seal to prevent turbulent flow orventuri action.

The combined lengths of the recesses 12 and 13 are somewhat less thanthat of the tubular member 11 so that when the joint is completed bytightening the nuts 21 on the studs 20, as shown in FIG. 2, longitudinalcompressional pressure is exerted on the beveled ends of the tubularmember. Recessed from either beveled end of the tubular member is anannular groove 24 and 25, respectively, to provide marginal nosesections 26 and 27. respectively, relatively more flexible than otherparts of the member. By these means there is substantially prevented thetransmission of distortion to the central section 28 of the member llunder the compressional stress which might otherwise result frommisalignment, machining variations or other factors. As will become moreapparent hereinafter, nose sections 26 and 27 will also function toretard the longitudinal or axial expansion of pipe sections l4 and 15.

The annular surface of recesses 12 and I3 generally conform to theexterior shape of central section 28 of tubular member II in the areabetween marginal grooves 24 and 25 but slope away at a suitable anglefrom the exterior surface of tubular member II in the regions betweengrooves 24, 25 and beveled ends 22, 23, respectively, thereby formingannular shoulders 36, 38 substantially in alignment with grooves 24, 25,and annular pockets 42, 44. In a preferred embodiment the angle of slopeis chosen at l0. However, any suitable angle can be chosen withoutdeparting from the spirit and scope of the invention.

The inner ends 16 and 17 of recesses 12 and 13 are made slightly widerthan corresponding nose sections 26 and 27 to allow for a degree offlexibility of the nose sections. This flexibility concentrates thelongitudinal distortion of member 11 to nose sections 26 and 27permitting an exact mutual engagement between central section 28 and thecorresponding regions of recesses 12 and 13.

The surfaces of inner ends 16 and 17 of recesses 12 and 13 in oneembodiment of the present invention are blunt. However, in situationswhere member 11 is formed of hard metal and the pipe sections 14. and 15are formed of soft metal inner ends 16 and 17 are beveled, as shown indotted lines in FIG. 1, to substantially conform to the shape of beveledends 22 and23 of member 11. This prevents the beveled ends 22 and '23 ofmember 11 from digging in and catching on inner ends 16 and 17. p Inoperation the tubular member 11 is first in an unstressed state as shownin FIG. I. As nuts 21 or studs 20 are tightened inner ends 16 and 17press on beveled ends 22 and 23 on member 11, respectively, and therebycam or force nose sections 26' and 27 to be bent outwardly about grooves24 and 25 to completely fill and conform to the shape of annular pockets42 and 44 above and below shoulder means 36 and 38, respectively.Therefore, it can be seen that the shoulder means 36 and 38 inconjunction with nose sections 26 and 27, which are bent around saidshoulder, prohibit or retard the axial movement of pipe sections 14 and15. This is very important at extremely high temperatures since studs 20tend to axially expand at these temdue to the conforming nature ofmember 11 about shoulders 36 and 38 of recesses 12 and 13.

Conventional surface seals (not shown) may be provided in grooves 31 and32 of the central section 28 on either side of the joint line. Inaddition an O-ring seal may be provided in groove 40.

By these means it will be apparent that there is provided a stressedseal which yields to a degree under changes in the joint such as may bedue to temperature, bending, etc. without interfering with the sealingof the joint. In addition the conforming nature of the seal aboutshoulders 36 and 38 retards any axial completion of pipe sections 14 and15. It is to be understood, however, that the stressing of the sealmember should always be within its elastic limit so as to permit it tofunction. properly.

The tubular member I] may be made of any suitable metal, such as steel,and may be coated with different types of plastic flow or elasticmaterial such as Teflon, Hycar, rubber, plastic, etc. Alternatively, itmay be coated with silver, lead, zinc, cadmium, copper, etc. to providea redistributable surface and thereby a tighter joint. It will also beapparent that by the use of the tubular member 11 there is facilitatedthe bringing together of the ends of the pipes in proper alignment whenmaking up the joint.

In another embodiment, as shown in US. Pat. Re No. 27,389 issued June13, 1972, tubular member 11 may be provided with an external collarwhich extends between flanges 18 and 19. In that patent there is shownintegral with the central section 28 of the tubular member 11 a collar52 which extends outwardly between the flanges 18 and 19. When the studs20 are tightened the collar 52 is-secured between the flanges andresults in stiffening the tubular member. Shims or washers 50 aredisposed about the studs between the pipe flanges to prevent distortionof the flanges against the collar by the studs. Alternatively, as shownin the embodiment of FIG. 2, the collar may extend outwardly beyond thestuds 20 and be provided with aligned apertures 53 for the studs.

The parts are so proportioned that the thickness of the collar 52 isless than the difference between the lengthof the tubular member 11 andthe combined lengths of the recesses 12 and to a degree within theelastic limits of the parts stressed thereby.

This configuration may also be used with small sizes of pipe wheredesign criteria of the adjoining parts make it desirable.

I claim: 1. A pipe seal comprising a tubular member and a joint of twoaxially aligned pipes, said pipes having corresponding recesses in theiradjacent ends and means for closing the joint, said tubular memberhaving beveled ends and being inserted in said recesses with the saidbeveled ends of the tubular member engaging end walls of the recesses,the length of said tubular member being greater than the combinedlengths of said recesses, whereby the member is subjected tocompressional stress on closure of the joint, said member having endportions delineated by marginal outer radially extend ing annulargrooves to provide relatively resilient nose sections at said endportions under the compressional stress, said recesses includingshoulder means in substantial alignment with said annular grooves,whereby said nose sections are bent about said shoulders due to saidcompressional stress to preclude axial movement of said pipes.

2. A pipe seal as defined in claim 1 wherein said beveled ends of saidtubular member are sloped at such an angle that under compressionalstress the ends of said recesses press against said beveled ends and camsaid nose sections outwardly about said shoulder means in conformitywith the shape of said recesses.

. 3. A pipe seal as defined in claim 2-wherein the ends of said recessesare sloped at substantially the same angle as the beveled ends of saidtubular members.

4. A seal as defined by claim 1 in which the inside diameter of thetubular member is substantially the same as the inside diameter of thepipes.

5. A pipe seal as defined in claim 1 wherein said means for closing thejoint comprises threaded studs passing through apertures in externalflanges on the respective pipes.

6. A pipe seal as defined in claim wherein said recesses includeoutwardly sloping annular pockets in the regions between said annulargrooves and the ends of said recesses, one endof said pockets definingsaid shoulder means.

7. A pipe joint as defined by claim I and a stabilizing collar integralwith the central section of the member, said collar extending radiallyoutward, the thickness of the collar being less than the differencebetween the length of the tubular member and the combined lengths of therecesses.

8. A seal as defined by claim 7 in which the stabilizing collar extendsoutwardly a distance less than the studs and shim means between the pipeflanges adjacent said studs.

9. A seal as defined by claim 7 in which the collar extends outwardlybeyond the studs, said collar having apertures aligned withthe studs.

e s s e s

1. A pipe seal comprising a tubular member and a joint of two axiallyaligned pipes, said pipes having corresponding recesses in theiradjacent ends and means for closing the joint, said tubular memberhaving beveled ends and being inserted in said recesses with the saidbeveled ends of the tubular member engaging end walls of the recesses,the length of said tubular member being greater than the combinedlengths of said recesses, whereby the member is subjected tocompressional stress on closure of the joint, said member having endportions delineated by marginal outer radially extending annular groovesto provide relatively resilient nose sections at said end portions underthe compressional stress, said recesses including shoulder means insubstantial alignment with said annular grooves, whereby said nosesections are bent about said shoulders due to said compressional stressto preclude aXial movement of said pipes.
 2. A pipe seal as defined inclaim 1 wherein said beveled ends of said tubular member are sloped atsuch an angle that under compressional stress the ends of said recessespress against said beveled ends and cam said nose sections outwardlyabout said shoulder means in conformity with the shape of said recesses.3. A pipe seal as defined in claim 2 wherein the ends of said recessesare sloped at substantially the same angle as the beveled ends of saidtubular members.
 4. A seal as defined by claim 1 in which the insidediameter of the tubular member is substantially the same as the insidediameter of the pipes.
 5. A pipe seal as defined in claim 1 wherein saidmeans for closing the joint comprises threaded studs passing throughapertures in external flanges on the respective pipes.
 6. A pipe seal asdefined in claim 1 wherein said recesses include outwardly slopingannular pockets in the regions between said annular grooves and the endsof said recesses, one end of said pockets defining said shoulder means.7. A pipe joint as defined by claim 1 and a stabilizing collar integralwith the central section of the member, said collar extending radiallyoutward, the thickness of the collar being less than the differencebetween the length of the tubular member and the combined lengths of therecesses.
 8. A seal as defined by claim 7 in which the stabilizingcollar extends outwardly a distance less than the studs and shim meansbetween the pipe flanges adjacent said studs.
 9. A seal as defined byclaim 7 in which the collar extends outwardly beyond the studs, saidcollar having apertures aligned with the studs.